Mercury Levels Same in Autistic, Other Children
Fish Consumption Predicted Levels Best, Researchers Found
Mercury Levels: Study Findings
The autism group did not differ from the typically developing group in the
level of mercury circulating in their blood after the researchers adjusted for
the sources of mercury, Hertz-Picciotto says.
''There are no obvious differences in the circulating levels of mercury"
among the three groups, she says.
"Unadjusted, those with autism had lower levels as it turns out," she says.
That may be due to a lower consumption of fish among those with autism, she
says, perhaps because of the tendency to be picky eaters and adhere to the same
The average levels of mercury were 0.24 micrograms per liter for the
typically developing children, 0.26 micrograms per liter for those with autism
or autism spectrum disorder, and
0.16 micrograms for those with other developmental disorders, she found.
To put that in perspective, Hertz-Picciotto says the Environmental
Protection Agency considers a level of 5.8 micrograms per liter not risky
for pregnant women. There is no
specific standard set for children, she says.
Mercury Levels and Autism: Other Opinions
The new study drew mixed reactions from experts. The new findings ''should
be reassuring to parents," says Geraldine Dawson, PhD, chief science officer
for Autism Speaks and a research professor at the University of North Carolina,
''There has been concern by some parents that just the normal kind of
exposure to mercury in our environment ... might have a bigger effect on
children with autism, and they might have specific trouble metabolizing
mercury,” Dawson says.
''This [study] suggests that children with autism are not retaining high
levels of mercury in their body,” she says. “This study does not address the
issue of whether mercury played a role in causing autism."
Sallie Bernard, co-founder and executive director of the Coalition for
SafeMinds, called the study interesting but limited in its worth. "I think this
is a study that adds to the literature on mercury and autism," she says. "But
because it is looking at post-diagnosis exposure and does not investigate
unique susceptibility and different toxicokinetics [such as absorption] of
children with an autism spectrum disorder, the value of the study in
understanding the role of mercury in autism is limited."
In a statement released by SafeMinds in response to the study, Bernard calls
for research to look at how children with autism may handle mercury exposures
differently, pointing to research suggesting children with autism may be more
susceptible to stressors such as mercury.